rescript-vscode

The official VSCode plugin for ReScript.

Prerequisite

bs-platform 8.2.0 installed locally in your project.

Installation

The plugin's on VSCode Marketplace. In VSCode, cmd-shift-p -> "Install Extensions", then find "rescript-vscode".

The plugin activates on .res and .resi files. If you've already got Reason-Language-Server installed, it's possible that the latter took precedence over this one. Make sure you're using this plugin ("ReScript syntax") rather than Reason-Language-Server ("BuckleScript syntax").

Features

• Syntax highlighting (.res, .resi).
• Formatting, with caveats:
  • Currently requires the file to be part of a ReScript project, i.e. with a bsconfig.json.
  • Cannot be a temporary file
• Syntax errors diagnosis (only after formatting).

Upcoming Features

• Formatting of temporary files
• Formatting of files outside of a ReScript project root
• Type diagnosis

Develop

Other Editors With Language-Server Support

This repo happens to also contain a language-server usable by other editors. If you'd like to use this language-server with e.g. Atom, for now, you have to clone the repo and run npm run compile. The language server will be at server/out/server.js. Wire that into your editor.

Structure

.
├── client // Language Client
│   ├── src
│   │   └── extension.ts // Language Client entry point
├── package.json // The extension manifest.
└── server // Language Server
    └── src
        └── server.ts // Language Server entry point

Running the Project

• Run npm install in this folder. This installs all necessary npm modules in both the client and server folder
• Open VS Code on this folder.
• Press Ctrl+Shift+B to compile the client and server.
• Switch to the Debug viewlet (command palette -> View: Show Run and Debug).
• Select Launch Client from the drop down.
• Run the launch config.
• If you want to debug the server as well use the launch configuration Attach to Server
• In the [Extension Development Host] instance of VSCode, open a document in 'plain text' language mode.
• Try ReScript mode formatting with .res or .resi files.

Change the Grammar

• Modify grammars/rescript.tmLanguage.json.

Currently the best way to test it is to link your extension to ~/.vscode/extensions then reload a separate test VSCode .res tab after each grammar change.

For more grammar inspirations, check:

• TypeScript's grammar
• Writing a TextMate Grammar: Some Lessons Learned